#
# Boost Software License - Version 1.0 - August 17th, 2003
#
# Permission is hereby granted, free of charge, to any person or organization
# obtaining a copy of the software and accompanying documentation covered by
# this license (the "Software") to use, reproduce, display, distribute,
# execute, and transmit the Software, and to prepare derivative works of the
# Software, and to permit third-parties to whom the Software is furnished to
# do so, all subject to the following:
# 
# The copyright notices in the Software and this entire statement, including
# the above license grant, this restriction and the following disclaimer,
# must be included in all copies of the Software, in whole or in part, and
# all derivative works of the Software, unless such copies or derivative
# works are solely in the form of machine-executable object code generated by
# a source language processor.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
# SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
# FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
#
# 2012-01-31, Lars Bilke
# - Enable Code Coverage
#
# 2013-09-17, Joakim Söderberg
# - Added support for Clang.
# - Some additional usage instructions.
#
# 2016-11-02, Azat Khuzhin
# - Adopt for C compiler only (libevent)
#
# USAGE:
# 1. Copy this file into your cmake modules path.
#
# 2. Add the following line to your CMakeLists.txt:
#      INCLUDE(CodeCoverage)
#
# 3. Set compiler flags to turn off optimization and enable coverage: 
#    SET(CMAKE_CXX_FLAGS "-g -O0 -fprofile-arcs -ftest-coverage")
#	 SET(CMAKE_C_FLAGS "-g -O0 -fprofile-arcs -ftest-coverage")
#  
# 3. Use the function SETUP_TARGET_FOR_COVERAGE to create a custom make target
#    which runs your test executable and produces a lcov code coverage report:
#    Example:
#	 SETUP_TARGET_FOR_COVERAGE(
#				my_coverage_target  # Name for custom target.
#				test_driver         # Name of the test driver executable that runs the tests.
#									# NOTE! This should always have a ZERO as exit code
#									# otherwise the coverage generation will not complete.
#				coverage            # Name of output directory.
#				)
#
# 4. Build a Debug build:
#	 cmake -DCMAKE_BUILD_TYPE=Debug ..
#	 make
#	 make my_coverage_target
#
#

# Check prereqs
FIND_PROGRAM( GCOV_PATH gcov )
FIND_PROGRAM( LCOV_PATH lcov )
FIND_PROGRAM( GENHTML_PATH genhtml )
FIND_PROGRAM( GCOVR_PATH gcovr PATHS ${CMAKE_SOURCE_DIR}/tests)

IF(NOT GCOV_PATH)
	MESSAGE(FATAL_ERROR "gcov not found! Aborting...")
ENDIF() # NOT GCOV_PATH

IF(NOT CMAKE_COMPILER_IS_GNUCC)
	# Clang version 3.0.0 and greater now supports gcov as well.
	MESSAGE(WARNING "Compiler is not GNU gcc! Clang Version 3.0.0 and greater supports gcov as well, but older versions don't.")
	IF(NOT "${CMAKE_C_COMPILER_ID}" STREQUAL "Clang" AND NOT "${CMAKE_C_COMPILER_ID}" STREQUAL "AppleClang")
		MESSAGE(FATAL_ERROR "Compiler is not GNU gcc! Aborting...")
	ENDIF()
ENDIF() # NOT CMAKE_COMPILER_IS_GNUCC


# Param _targetname     The name of new the custom make target
# Param _testrunner     The name of the target which runs the tests.
#						MUST return ZERO always, even on errors. 
#						If not, no coverage report will be created!
# Param _outputname     lcov output is generated as _outputname.info
#                       HTML report is generated in _outputname/index.html
# Optional fourth parameter is passed as arguments to _testrunner
#   Pass them in list form, e.g.: "-j;2" for -j 2
FUNCTION(SETUP_TARGET_FOR_COVERAGE _targetname _testrunner _outputname)

	IF(NOT LCOV_PATH)
		MESSAGE(FATAL_ERROR "lcov not found! Aborting...")
	ENDIF() # NOT LCOV_PATH

	IF(NOT GENHTML_PATH)
		MESSAGE(FATAL_ERROR "genhtml not found! Aborting...")
	ENDIF() # NOT GENHTML_PATH

	# Setup target
	ADD_CUSTOM_TARGET(${_targetname}
		
		# Cleanup lcov
		${LCOV_PATH} --directory . --zerocounters
		COMMAND ${CMAKE_COMMAND} -E remove ${_outputname}.info ${_outputname}.info.cleaned

		# Run tests
		COMMAND ${_testrunner} ${ARGV3}
		
		# Capturing lcov counters and generating report
		COMMAND ${LCOV_PATH} --directory . --capture --output-file ${_outputname}.info
		COMMAND ${LCOV_PATH} --remove ${_outputname}.info '*/test/*' '/usr/*' --output-file ${CMAKE_BINARY_DIR}/${_outputname}.info.cleaned
		COMMAND ${GENHTML_PATH} -o ${_outputname} ${_outputname}.info.cleaned
		
		WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
		COMMENT "Resetting code coverage counters to zero.\nProcessing code coverage counters and generating report."
	)
	
	# Show info where to find the report
	ADD_CUSTOM_COMMAND(TARGET ${_targetname} POST_BUILD
		COMMAND ;
		COMMENT "Open ./${_outputname}/index.html in your browser to view the coverage report."
	)

ENDFUNCTION() # SETUP_TARGET_FOR_COVERAGE

# Param _targetname     The name of new the custom make target
# Param _testrunner     The name of the target which runs the tests
# Param _outputname     cobertura output is generated as _outputname.xml
# Optional fourth parameter is passed as arguments to _testrunner
#   Pass them in list form, e.g.: "-j;2" for -j 2
FUNCTION(SETUP_TARGET_FOR_COVERAGE_COBERTURA _targetname _testrunner _outputname)

	IF(NOT PYTHON_EXECUTABLE)
		MESSAGE(FATAL_ERROR "Python not found! Aborting...")
	ENDIF() # NOT PYTHON_EXECUTABLE

	IF(NOT GCOVR_PATH)
		MESSAGE(FATAL_ERROR "gcovr not found! Aborting...")
	ENDIF() # NOT GCOVR_PATH

	ADD_CUSTOM_TARGET(${_targetname}

		# Run tests
		${_testrunner} ${ARGV3}

		# Running gcovr
		COMMAND ${GCOVR_PATH} -x -r ${CMAKE_SOURCE_DIR} -e '${CMAKE_SOURCE_DIR}/tests/'  -o ${_outputname}.xml
		WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
		COMMENT "Running gcovr to produce Cobertura code coverage report."
	)

	# Show info where to find the report
	ADD_CUSTOM_COMMAND(TARGET ${_targetname} POST_BUILD
		COMMAND ;
		COMMENT "Cobertura code coverage report saved in ${_outputname}.xml."
	)

ENDFUNCTION() # SETUP_TARGET_FOR_COVERAGE_COBERTURA
